The present invention relates to an automatic coupling device suitable for connecting an externally splined power take-off shaft to a corresponding internally splined yoke with a universal joint and particularly to a coupling mechanism which incorporates an automatic release to the locked position and locks axially onto the shaft by way of locking balls.
The problem of coupling one shaft to another for transmitting a torque force is a problem that has long existed in the agricultural industry. Agricultural tractors are normally equipped with a splined power take-off shaft to which the shaft of a towed or mounted agricultural implement is connected by means of a coupling mechanism which conventionally includes an internally splined member mating with the splined power take-off shaft and having a universal joint. Such mechanisms also generally include a releasable lock for preventing the inadvertent axial separation of the mating splined members. Examples of such torque transmitting couplings are disclosed in U.S. Pat. Nos. 3,357,206 - Christie, 3,551,013 - Trojanowski et al, 4,289,414 - Recker and 4,402,626 - Recker. While the foregoing coupling mechanisms have been satisfactory in their operation, they have left something to be desired.
The present coupling device provides a simplified operation for use where once the mechanism is unlocked, the mechanism functions with a "no-hands" locking feature. Additionally, the present coupling device utilizes a collar design which totally encloses the torsional spring, locking elements and locking mechanism thus resisting entry of any foreign matter into the mechanism.